JP6655741B1 - cap - Google Patents

Abstract

A cap capable of preventing blow-off and overrun is provided. A cap (1) attached to a container opening (M) so as to cover the container opening (M), comprising a top wall (2) and a substantially cylindrical skirt extending downward from an outer peripheral portion of the top wall (2). The skirt wall 3 is provided with a female screw 5 that is screwed into a male screw M1 formed on the outer periphery of the container mouth M. The skirt wall 3 is located below the female screw 5 on the skirt wall 3. The thickness of the lower part 14 is larger than the thickness of the upper part 15 located above the female screw 5. [Selection] Figure 2

Description

  The present invention relates to, for example, a cap attached to a mouth of a container for storing contents such as a beverage.

  As shown in FIGS. 3 (A) and 3 (B), the cap 51 which is detachably attached to the mouth M of the container by screw connection and is configured to take on the function of closing and opening the mouth M of the container. It is widely used for containers for various beverages and the like (Patent Document 1).

Japanese Patent No. 5291175

  By the way, in the conventional cap 51 attached to the container mouth M by screw connection, the opening range (area) of the female screw 52 of the cap 51 with the male screw M1 of the container mouth M narrows with the opening operation. However, as long as the male screw M1 and the female screw 52 are engaged, the cap 51 does not come off from the container mouth M. However, for example, when the container is filled with a carbonated beverage, the internal pressure of the container is increased by the gas pressure derived from carbon dioxide, whereby the cap 51 is pushed up while the male screw M1 and the female screw 52 are engaged. When the diameter of the skirt wall 53 of the cap 51 is increased to the extent that the skirt wall 53 can get over the male screw M1 and the engagement is released, a phenomenon called blow-off occurs in which the cap is popped off.

  In addition, in the above-mentioned conventional cap, when the cap is attached to the container mouth, if the cap is excessively tightened, an overrun (the female screw of the cap gets over the male screw of the container mouth) occurs, and the cap is insufficiently closed. There is a risk of becoming.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned matters, and an object of the present invention is to provide a cap capable of preventing blow-off and overrun.

In order to achieve the above object, a cap according to the present invention is a cap that is attached to a container mouth so as to cover the container mouth, and has a top wall and a downward direction from an outer peripheral portion of the top wall. A substantially cylindrical skirt wall extending therefrom, wherein an outer portion of a corner formed by the top wall and the skirt wall is not depressed inward, and the skirt wall has an outer periphery of a container mouth portion. screwed internal thread is provided on the male thread which is formed, in the skirt wall, the thickness of the lower portion located below the female screw, larger than the thickness of the upper part located above the internal thread, wherein In the skirt wall, the inner peripheral surface of the lower portion extends away from the outer peripheral surface toward the lower side, and the lowermost portion continuing below the lower portion has an inner diameter that increases toward the lower side. The rate of change of the inner diameter at It is larger than the change rate of the inner diameter of the vertical direction (Claim 1).

Further, in the cap, in a region from the upper portion to the lower portion of the skirt wall, the thickness of a portion excluding the female screw may be increased toward the lower side (claim 2) .
Also, the tamper evidence band via an annular weakening is connected to a lower portion of the skirt wall, said on the inner peripheral side of the tamper evidence band, annular formed below the external thread in the outer periphery of the container mouth part The projection may be provided with an engagement portion configured to be lockable from below (claim 3 ).

  According to the present invention, a cap capable of preventing blow-off and overrun can be obtained.

  That is, in the cap of the present invention, the thickness of the lower portion is made larger than the thickness of the upper portion. It is difficult to expand and deform. Therefore, for example, when the container is filled with a carbonated beverage, the internal pressure of the container is increased by the gas pressure derived from the carbon dioxide gas, whereby the male screw of the container mouth and the female screw of the cap are engaged. Even if a pushing force is applied to the cap as it is, since the skirt wall is difficult to expand as described above, it is prevented that the skirt wall expands to the extent that it can get over the male screw and the engagement is disengaged. The occurrence of blow-off can be prevented.

  Further, due to the difficulty in increasing the diameter of the skirt wall, it is possible to prevent the occurrence of overrun (that the female screw of the cap gets over the male screw of the container mouth).

  On the other hand, if the thickness of the portion of the skirt wall excluding the female screw in the female screw forming region where the female screw is formed is less than or equal to the thickness of the upper portion, the diameter increases in this female screw forming region, and blow-off and overrun occur. However, in the cap according to the second aspect of the present invention, the female screw is removed in a region from the upper portion to the lower portion (including the female screw forming region) of the skirt wall. Since the thickness of the portion is made larger as it goes downward, the occurrence of blow-off and overrun can be sufficiently prevented.

(A) is a bottom view schematically showing the configuration of the cap according to one embodiment of the present invention, and (B) is a cross-sectional view taken along line AA of (A). FIG. 2 is a sectional view taken along line BB in FIG. 1A is a front view showing a conventional synthetic resin cap, and FIG. 1B is a front view showing a state where the cap is attached to a container opening.

  Embodiments of the present invention will be described below with reference to the drawings.

  A synthetic resin cap (hereinafter referred to as a cap) 1 shown in FIGS. 1A and 1B is a container having a male screw M1 and an annular protrusion (an example of an engaged portion) M2 as shown in FIG. 3B. A mouth M (for example, a mouth of a container such as a PET bottle) is used so as to be attached so as to cover the mouth M, and is integrally formed of polyethylene by compression molding or injection molding. In addition, the material for forming the cap 1 is not particularly limited. In addition to the polyethylene used in the present embodiment, polypropylene or the like is preferably used.

  The cap 1 has a top wall 2 having a substantially circular shape in a plan view, and a substantially cylindrical skirt wall 3 extending downward from an outer peripheral portion of the top wall 2 (see FIGS. 1A and 1B). Here, as shown in FIG. 1 (B), a knurled groove 4 is provided on the outer peripheral surface of the skirt wall 3 and a female screw 5 is provided on the inner peripheral surface. Can be connected to the set external thread M1.

  When the cap 1 is rotated and attached to the container mouth M so that the female screw 5 of the skirt wall 3 is connected to the male screw M1 of the container mouth M, the inner surface (lower surface) of the top wall 2 shown in FIG. An annular middle foot (inner ring) 6, an annular rib 7, and an annular outer foot (outer ring) 8 are closely attached to the container opening M, thereby the container opening M is sealed. Become. That is, when the cap 1 is attached to the container mouth M, the middle foot 6 is inserted into the container mouth M and closely adheres to the inner peripheral surface of the container mouth M, and the annular rib 7 is attached to the container mouth M. The outer foot 8 is configured to be in close contact with the outer peripheral surface of the container mouth portion M while being in close contact with the annular upper end surface.

  The cap 1 is a pill fur proof cap having a function to prove that the cap 1 has not been opened (the cap has never been opened). When the cap 1 is rotated so that the connection between the male screw M1 and the female screw 5 is released at the time of opening, the cap 1 is detached from the container mouth M, but the tamper evidence connected to the lower part of the skirt wall 3 is obtained. The band (hereinafter, simply referred to as “band”) 9 (see FIG. 1B) is configured to remain in the container opening M.

  That is, a band 9 is connected to the lower part of the skirt wall 3 via an annular weakening portion 10 extending over the entire circumference of the skirt wall 3 (see FIG. 1B). (A perforated) slit intermittently extending in the circumferential direction of the skirt wall 3 and the band 9 so as to define the upper and lower portions of the skirt wall 3 and the band 9, and a bridge (bridge) existing between adjacent slits. The bridge breaks when pulled with a predetermined force.

  Here, in this example, the outer diameter of the band 9 is made uniform over the upper and lower sides, while the band 9 is configured to protrude inward on the inner peripheral side, and the amount of inward protrusion increases toward the upper side. Five (an example of a plurality of) hooks (an example of an engagement portion) 11 are provided at intervals (equal intervals in this example) in the circumferential direction (see FIGS. 1A and 1B). Each hook 11 is substantially below an annular projection M2 (see FIG. 3B) formed below the male screw M1 on the outer periphery of the container mouth M when the cap 1 is attached to the container mouth M. And locked to the annular projection M2 by the opening operation. That is, the hook 11 is configured to be able to be locked to the annular projection M2 from below. The two-dot chain line at the bottom of FIG. 2 shows the cross-sectional shape of the portion where the hook 11 is not provided.

  Further, as shown in FIGS. 1B and 2, on the inner peripheral side of the band 9, the upper end of the hook 9 protrudes inward from the inner surface of the upper end of the band 9, and the maximum amount of protrusion is (The inner diameter is larger than the inner diameter of the hook 11) is provided over the entire circumference of the band 9, and the inclined portion having an inner diameter that is larger toward the upper side above the fitting portion 12 is provided. 13 are connected.

  Thus, in the unopened state attached to the container mouth M, the annular projection M2 is positioned inside or above the inclined portion 13, and when the cap 1 is rotated in the opening direction from this state, the container mouth M is opened. The cap 1 is relatively raised with respect to M, the fitting portion 12 is fitted into the annular projection M2, and the hook 11 is locked to the annular projection M2 from below. When the cap 1 is further rotated in the opening direction, the annular weakened portion 10 is eventually broken, and the band 9 remains in the container opening M, while the cap body composed of the top wall 2 and the skirt wall 3 above the container is a container. It will be detached from the mouth M.

  Therefore, before the hook 11 is engaged with the annular projection M2 from below, the inclined portion 13 contacts the annular projection M2, and the fitting portion 12 is fitted to the outer peripheral surface of the annular projection M2. Thereby, the band 9 is prevented from lifting obliquely, and the annular weakened portion 10 breaks substantially uniformly without bias, so that the tamper-evidence property is improved. When the stopper is opened, the fitting portion 12 is fitted on the outer peripheral surface of the annular projection M2 of the container mouth M, and the hook 11 is securely engaged with the annular projection M2, so that the annular weakening portion 10 is broken. Thus, it is possible to prevent the hook 11 from getting over the annular protrusion M2, that is, to prevent the so-called slip-through.

  In this example, as shown in FIG. 2, in the skirt wall 3, the thickness of the lower portion 14 located below the female screw 5 (the female screw forming region 5 </ b> A) is reduced by the thickness of the upper portion 15 located above the female screw 5. It is larger than the wall thickness.

  Here, the lower part 14 is a part that continues below the female screw 5 (female screw forming area 5A) on the skirt wall 3. The inner peripheral surface of the lower portion 14 extends so as to be further away from the outer side (outer peripheral surface) toward the lower side. Further, the inner diameter of the lowermost part 16 which continues below the lower part 14 is increased toward the lower side, and the change rate of the inner diameter in the vertical direction is larger than the change rate of the inner diameter in the vertical direction of the lower part 14. ing.

  On the other hand, the upper part 15 is a part that continues above the female screw 5 (female screw forming area 5A) on the skirt wall 3. Further, the inner peripheral surface of the upper portion 15 also extends so as to be further away from the outer side (outer peripheral surface) toward the lower side. Above the upper portion 15, a corner portion 17 extending so that the inner peripheral surface and the outer peripheral surface are bent inward is continuous.

  Since the female screw 5 extends spirally on the inner peripheral surface of the skirt wall 3, the position and the vertical width of the female screw 5 (female screw forming region 5A) are not uniform in the circumferential direction of the skirt wall 3. Depending on the phase, the upper and lower widths of the lower portion 14 and the upper portion 15 also differ depending on the phase.

  As described above, in the present example, the thickness of the lower portion 14 is larger than the thickness of the upper portion 15, so that the thickness of the lower portion 14 is smaller than or equal to the thickness of the upper portion 15. The skirt wall 3 is less likely to expand and deform. Therefore, for example, when the container is filled with a carbonated beverage, the internal pressure of the container is increased by the gas pressure derived from the carbon dioxide gas, so that the male screw M1 and the female screw 5 are engaged with the cap 1 in the engaged state. Even if a push-up force is applied, the skirt wall 3 is difficult to expand as described above, so that the skirt wall 3 is prevented from being disengaged by expanding the diameter of the skirt wall 3 to the extent that the skirt wall 3 can get over the male screw M1. The occurrence of blow-off can be prevented.

  Further, due to the difficulty in increasing the diameter of the skirt wall 3, it is possible to prevent the occurrence of overrun (when the female screw of the cap passes over the male screw of the container mouth).

  On the other hand, if the thickness of the portion excluding the female screw 5 in the female screw forming region 5A is equal to or less than the thickness of the upper portion 15, the diameter is increased in the female screw forming region 5A to prevent the occurrence of blow-off and overrun. In this example, the wall thickness of the portion excluding the female screw 5 in the region from the upper portion 15 to the lower portion 14 (including the female screw forming region 5A) of the skirt wall 3 may be insufficient. Since it becomes larger toward the lower side, the occurrence of blow-off and overrun can be sufficiently prevented. In addition, the two-dot chain line shown in the upper part of FIG.

  It should be noted that the present invention is not limited to the above-described embodiment at all, and it is needless to say that various modifications can be made without departing from the spirit of the present invention. For example, the following modifications can be given.

  In the example of FIG. 2, from the upper end of the upper part 15 to the lower end of the lower part 14, the thickness of the part excluding the female screw 5 is made to increase at a constant rate toward the bottom, but is not limited thereto. The ratio may be changed on the way, or a portion where the thickness of the portion excluding the female screw 5 does not change in the vertical direction may be provided.

  In addition, between the lower part 14 and the lowermost part 16, a part that does not correspond to either the lower part 14 or the lowermost part 16 may be provided, or the lower part 14 may be provided without the lowermost part 16. May continue to the lower end of the skirt wall 3.

  Between the upper part 15 and the corner part 17, a part which does not correspond to any of the upper part 15 and the corner part 17 may be provided.

  It goes without saying that the above-mentioned modifications may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 Cap 2 Top wall 3 Skirt wall 4 Knurl groove 5 Female screw 5A Female screw formation area 6 Middle foot 7 Annular rib 8 Outer foot 9 Tamper evidence band 10 Annular weakening part 11 Hook (engagement part)
12 Fitting part 13 Inclined part 14 Lower part 15 Upper part 16 Lower part 17 Corner part 51 Cap 52 Female screw M Container mouth M1 Male screw M2 Annular projection (engaged part)

Claims (3)

A cap attached to the container mouth to cover the container mouth,
The ceiling wall,
A substantially cylindrical skirt wall extending downward from an outer peripheral portion of the top wall,
The outer part of the corner formed by the top wall and the skirt wall is not depressed inward,
The skirt wall is provided with a female screw that is screwed into a male screw formed on the outer periphery of the container mouth,
In the skirt wall, the thickness of a lower portion located below the female screw is made larger than the thickness of an upper portion located above the female screw ,
In the skirt wall, the inner peripheral surface of the lower portion extends away from the outer peripheral surface toward the lower side, and the innermost surface extending below the lower portion has an inner diameter that increases toward the lower side. The cap , wherein the rate of change of the inner diameter in the direction is larger than the rate of change of the inner diameter in the vertical direction of the lower part .   2. The cap according to claim 1, wherein in a region from the upper portion to the lower portion of the skirt wall, a thickness of a portion excluding the female screw increases toward a lower portion. 3. A tamper evidence band is connected to a lower portion of the skirt wall via an annular weakening portion. The cap according to claim 1 , further comprising an engagement portion configured to be able to be locked from the cap.